Tobacco use and tobacco-caused illnesses and death are increasing in developing countries globally, so it is critical to study these countries in order to effectively address the tobacco epidemic. The proposed project will test the effectiveness of community-based interventions for secondhand smoke and quitting smoking in eight underserved communities in the Dominican Republic. The project will also partner with communities and national and international groups to determine whether the methods and interventions from this study in the Dominican Republic can also be used to help other countries in the region and underserved groups in the United States.